Adjustable mechanism for thermo shrinkable film machine

ABSTRACT

A thermo shrinkable film machine includes two blocks movably mounted on two rails between two sideswalls on the base of the machine. A rotatable rod is rotatably connected between the two sidewalls includes a right-handed threaded section and a left-handed threaded section. The two blocks has two respective threaded passages which are respectively connected to the right-handed threaded section and the left-handed threaded section so that when rotating the rotatable rod, the two blocks are moved in opposite directions. Two wheels are respectively connected to the two blocks so as to contact thermo shrinkable film mounted on a shaft. An adjustable mechanism includes a driving wheel connected to an end of the rotatable rod and can be positioned by a positioning unit received in one of the two sidewalls.

FIELD OF THE INVENTION

The present invention relates to an adjustable mechanism for micro-adjusting the wheels for transmitting the thermo shrinkable film of different thickness.

BACKGROUND OF THE INVENTION

A conventional thermo shrinkable film machine generally includes a transmission wheel with a hole defined centrically therethrough and a shaft rotatably extends through the hole in the transmission wheel with a small gap defined between the inner periphery of the hole and the shaft. Two upper pressing wheels are located around the shaft so as to provide proper pressure on the thermo shrinkable film and to move film downward along the shaft. A cutting device is located beneath the transmission wheel so as to cut the film at pre-decided length. A positioning device is located beneath the transmission wheel and includes two lower pressing wheels which guide the film to be mounted to containers or cans. Two flexible plates are used to stop lower edge of the film which is not yet sent to mount on the containers or cans. A common problem is that the thickness of the film may vary due to the different manufacturers and the upper pressing and lower pressing wheels have to be adjusted accordingly by manual efforts and this spends a lot of time.

The present invention intends to provide an adjustable mechanism for micro adjusting the pressing wheels for the shrinkable film of different thickness.

SUMMARY OF THE INVENTION

The present invention relates to a thermo shrinkable film machine which comprises a base with two sidewalls and two rails are connected between the two sidewalls. A rotatable rod is rotatably connected between the two sidewalls and located between the two rails. The rotatable rod includes a right-handed threaded section and a left-handed threaded section. Two blocks are movably mounted to the two rails and have two respective threaded passages so as to be engaged with the right-handed threaded section and the left-handed threaded section respectively. Two wheels are respectively connected to the two blocks so as to contact thermo shrinkable film mounted on a shaft. A positioning unit received in one of the two sidewalls and a driving wheel which is connected to an end of the rotatable rod. The driving wheel is positioned by the positioning unit.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view to show the thermo shrinkable film machine and the adjustable mechanism of the present invention;

FIG. 2 is a perspective view to show the thermo shrinkable film machine and the adjustable mechanism of the present invention;

FIG. 3 is a cross sectional view to show that the bead is engaged with one of the notches in the driving wheel;

FIG. 4 shows when rotating the driving wheel, the bead is removed from the notch of the driving wheel;

FIG. 5 shows the bead is engaged with another notch of the driving wheel so as to adopt the wheels on the two blocks to the thicker film;

FIG. 6 is another embodiment of the adjustable mechanism of the present invention, and

FIG. 7 is yet another embodiment of the adjustable mechanism of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1 to 3, the thermo shrinkable film machine 2 of the present invention comprises a base with two sidewalls 21, 22 on the base 20 and a transmission wheel 60 for driving a shaft 6 is rotatably engaged with a recess in a side of the base 20. Two rails 23, 24 are connected between the two sidewalls 21, 22 and a rotatable rod 3 is rotatably connected between the two sidewalls 21, 22 and located between the two rails 23, 24. The rotatable rod 3 includes a right-handed threaded section 31 and a left-handed threaded section 32. Two blocks 26, 27 are movably mounted to the two rails 23, 24 and have two respective threaded passages. The right-handed threaded section 31 and the left-handed threaded section 32 are respectively threadedly engaged with the two respective threaded passages such that when rotating the rotatable rod 3, the two blocks 26, 27 are moved in two opposite directions along the two rails 23, 24. Two wheels 260, 270 are respectively connected to the two blocks 26, 27 so as to contact the thermo shrinkable film 7 mounted on the shaft 6.

An adjustable mechanism includes a positioning unit 5 received in a hole 210 in the sidewall 21 and a driving wheel 4 has a rectangular hole through which a rectangular section on an end of the rotatable rod 3 extends. The driving wheel 4 has a plurality of notches 40 defined in a side thereof. The positioning unit 5 includes a bead 50 and a spring 51 which biases the bead 50. The bead 50 and the spring 51 are received in a sleeve 52 which has a smaller opening in one end of the sleeve 52 so as to prevent the bead 50 from dropping from the sleeve 52. The bead 50 is engaged with one of the notches 40 of the driving wheel 4.

Referring to FIGS. 4 and 5, when the film 7 to be used is thicker than the previous one, the user may rotating the driving wheel 4 to move the two blocks 26, 27 away from each other, and the rotation can be stopped when the bead 50 is engaged with another notch 40. The small gap of adjustment between the wheels 260, 270 and the film 7 allows the wheels 260, 270 to contact the thicker film 7 properly.

Referring to FIG. 6 which shows another embodiment of the present invention wherein the driving wheel 4 includes an insertion which is rotatably extends through the sidewall 21, and a plurality of notches 40 are defined in an outer periphery of the insertion. The positioning unit 5 is received in a hole 210 defined in a top of the sidewall 21 so that a bead 50 is engaged with one of the notches 40 of the insertion of the driving wheel 4.

FIG. 7 shows yet another embodiment wherein the driving wheel 4 is connected to an end of the rotatable rod 3 and a plurality of protrusions 400 extending from a first side of the driving wheel 4. A hole 210 is defined in the sidewall 21 and receives one of the protrusions 400. The adjustable mechanism includes a positioning unit 5 which includes a spring 51 and a cap 52 which is fixed to the end of the rotatable rod 3. The spring 51 is biased between the driving wheel 4 and the cap 52 so as to provide a force to the driving wheel 4 toward the sidewall 21. A recess 41 is defined in the second side of the driving wheel 4 so as to accommodate the positioning unit 5 therein.

While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

1. A thermo shrinkable film machine comprising: a base with two sidewalls on the base, two rails connected between the two sidewalls and a rotatable rod rotatably connected between the two sidewalls, the rotatable rod including a right-handed threaded section and a left-handed threaded section, two blocks movably mounted to the two rails and having two respective threaded passages, the right-handed threaded section and the left-handed threaded section respectively threadedly engaged with the two respective threaded passages, two wheels respectively connected to the two blocks and adapted to contact thermo shrinkable film mounted on a shaft, and an adjustable mechanism including a positioning unit received in one of the two sidewalls and a driving wheel which is connected to an end of the rotatable rod, the driving wheel being positioned by the positioning unit.
 2. The machine as claimed in claim 1, wherein the driving wheel has a plurality of notches defined in a side thereof and the positioning unit is received in a hole in one of the two sidewalls, the positioning unit including a bead and a spring which biases the bead which is engaged with one of the notches of the driving wheel.
 3. The machine as claimed in claim 1, wherein the driving wheel 4 includes an insertion which is rotatably extends through one of the sidewalls, a plurality of notches defined in an outer periphery of the insertion, the positioning unit received in a hole in one of the two sidewalls and including a bead and a spring which biases the bead which is engaged with one of the notches of the insertion of the driving wheel.
 4. A thermo shrinkable film machine comprising: a base with two sidewalls on the base, two rails connected between the two sidewalls and a rotatable rod rotatably connected between the two sidewalls, the rotatable rod including a right-handed threaded section and a left-handed threaded section, two blocks movably mounted to the two rails and having two respective threaded passages, the right-handed threaded section and the left-handed threaded section respectively threadedly engaged with the two respective threaded passages, two wheels respectively connected to the two blocks and adapted to contact thermo shrinkable film mounted on a shaft, and a driving wheel mounted to an end of the rotatable rod and an adjustable mechanism including a positioning unit connected to a first side of the driving wheel, a plurality of protrusions extending from a second side of the driving wheel, a hole defined in one of the two sidewalls and receiving one of the protrusions, the positioning unit including a spring and a cap which is fixed to the end of the rotatable rod, the spring being biased between the driving wheel and the cap.
 5. The machine as claimed in claim 4, wherein the driving wheel has a recess defined in the first side of the driving wheel and the positioning unit is received in the recess. 